Conveyance construction



J y 1965 a. JONES ETAL CONVEYANCE CONSTRUCTION Filed Oct- 5, 1961INVENTORS CHARLES R. GRAY ATTORNEYS BOBBY L. JONES United States Patentration of Delaware Filed Get. 5, 1961, Ser. No. 143,088 12 Claims. (Cl.105-422) The present invention relates generally to freight carryingconveyances and more particularly to the structure of the flooring ofsuch conveyances.

For many years, in freight conveyances such as railway rolling stock,all-steel freight cars of the open top variety had been used providedwith floors comprised of steel plates fastened together. These gondolacars, as they are called, were fairly satisfactory for thetransportation of freight of a loose nature such as coal, grain, ironore, pig iron, or steel scrap or the like. Loose freight could simply bedumped into the car and transported without securement of any kind, thesteel floor providing underlying support for the freight and nothingmore.

However, for those types of lading which needed to be immobilized withrespect to the freight car for satisfactory transportation and thosewhich needed floating or restrained connection with the car, woodenfreight car floors had long been the only practical solution in bothopen top and box cars. In order to immobilize freight or to set it up infloating relation to such Wooden flooring of freight cars, variousblocking arrangements were used. Heavy wooden blocking was placed in aposition on the car floor where it would abut against the proper part ofthe lading and this heavy blocking was nailed in this position to thewooden floor with heavy nails. When the freight reached its destination,the blocking was ripped up in order to remove the freight from the car.

The old steel plate floors, which obviously could not be used inconnection with blocking, had fairly long life. On the other hand, woodcar floors did not. The impact forces of loading and unloading usingheavy clamshell buckets and magnets in open top cars and the fork trucksused for loading and unloading box cars soon ruined the wooden flooring.Moreover, Wooden flooring continuously used for blocking freightdeteriorated rapidly due to weakening by the numerous nail holes.

Thus, the railroads were obliged to buy two kinds of cars, steel floorand wood floor. But this initial double expense was not the onlydisadvantage, as the steel cars and wood cars often ran empty. Forexample, in the steel industry, pig iron and scrap steel came into theplants in the old steel bottom cars and the finished prodnot packaged toprevent damage in transportation went out in wooden bot-tom cars. Mostof the time the wooden bottom cars came in empty and the steel bottomcars went out empty because neither type of car alone could handle bothtypes of freight.

In an effort to provide a single all-purpose, stronger freight carflooring, it was proposed quite some time ago to provide steel flooringhaving inserts comprising wooden nailing strips, as in US. Patent Nos.986,422 of 1911 and 2,056,137 of 1936, in the hope of combining thestrength of steel with the nailability of wood. However, in spite of thegreat additional expense involved, this solution has not beensatisfactory because the nail holes were concentrated in the insertedstrips with the result that the wood broke up and deteriorated veryrapidly. Furthermore, all attempted combinations of wood and steel haveresulted in inordinate steel corrosion, possibly because the woodretains moisture and holds it in contact with steel surfaces.

In recent years, an all-metal flooring has been devel oped which isstrong and has good nailing properties.

This flooring is described in US. Patent No. 2,667,243 and comprisesmetal structural members arranged sideby-side to form the flooring of afreight conveyance. These structural members as illustrated in thatpatent have reinforcing webs along their opposite sides and one web isprovided with a male corrugation while the other web is provided with acomplementary female corrugation. When the structural members arearranged side-byside, the male and female corrugated members are inopposed spaced apart relationship to define therebetween a sinuousgroove into which nails can be driven and gripped.

This recent metal flooring has been a vast improvement over any freightcar flooring known theretofore. Nevertheless, it has been susceptible tovarious improvements to strengthen it and render it cheaper and easierto manufacture, and the present invention embodies several suchimprovements.

Accordingly, it is an object of the present invention to provide aconveyance flooring adapted to receive and retain nails, having improvedstrength characteristics under static or shock loads applied normal tothe plane of the freight-engaging surface of the flooring.

Another object of the present invention is the provision of flooring forfreight conveyances, adapted to receive and retain nails, which has highstrength per unit of cross-sectional area, thereby to enable the use oflighter and less expensive flooring than in the past.

The invention also contemplates the provision of flooring for freightconveyances which is better adapted to distribute vertical loads imposedthereon, thereby to reduce the maximum unit stresses imposed on theflooring and to make possible the use of lighter and less expensiveflooring.

Yet another object of the present invention is the provision of freightconveyance flooring having improved antiskid properties.

Finally, it is an object of the present invention to provide freightconveyance flooring which will be easy and inexpensive to manufactureand install and rugged and durable in use.

Other objects and advantages of the present invention will becomeapparent from a consideration of the following description, taken inconnection with the accompanying drawings, in which:

FIGURE 1 is a fragmentary perspective view of the interior of a lowercorrner of conveyance construction according to the present invention asembodied, for example, in a railway freight car;

FIGURE 2 is an enlarged fragmentary prospective view of a portion of theflooring of FIGURE 1;

FIGURE 3 is an enlarged transverse cross-sectional view of a flooringmember according to the embodiment of the present invention that isshown in FIGURES 1 and 2; and

FIGURE 4 is view similar to FIGURE 3 but showing another embodiment ofthe present invention.

Although the present invention is illustrated and will hereinafter bedescribed in connection with railway rolling stock it will beappreciated that it is susceptible of embodiment in conveyances of othertypes, such as motor trucks, ships, airplanes and the like. Furthermore,although the illustrated embodiment indicates the use of an integralhotor cold-rolled sheet metal structural member defining the outersurfaces of a major portion of the flooring member of the invention,this metallic member can also be in the form of an extrusion or can bebuilt up of component parts.

Referring now to the drawing in greater detail, there is shown inFIGURES 1-3 a first embodiment of the present invention, in the form ofrailway rolling stock comprising a conventional freight car of open topor box-car type hav- 7 I eraser? ,The' hearing carried by this conveyingsupporting struci 'ture'comprises a plurality of long,fnarrow,contiguous metallicstructural members 13 arranged side-by side andextending across the car transversely of the length of the car andsupportedon framemembers 7. In order to pro.-

vide a floor to withstand the hard usage, to which it'Wlll be subjectedin a freight conveyance such as a freight car,

the structural members 13 are preferably comprisedof steel, and have atleast most'of their width comprised each of a panel 15 having fiathorizontal coplanarside portions 17 one on either side of and extendinglongitudinallysubstant ially full length of each panel 15. Between eachpair of side portions 17 is a depressed central portion 19 of panel 15,each depressed central portion 19 havingapair of generally flat sideportions 21 and a flat horizontal bottom portion .23. Each side portion21 isjoined along its upper edge to the'inner edge of a horizontal-sideportion 17 by means of a rounded fillet-25, and is joined along itslower edge to an outer edge of bottom portion 23 by a fillet 27.Depressed central portion 19 is upwardly open arid is filled level withits top with a hardened plasti'cmaterial 2s. V

The sides of each metallic structural member 13 are comprised by'flatwebs 31 that extend generally away from the conveying supportingstructure and are perpendicular to the common plane of side portions 17of panel 15.

Webs 31 terminate downward each in an'in'wardly directed horizontalflange 33 extending substantially full length of the flooring member butterminating short of depressed;

central portion 19 of panel 15. Flanges 33 are coplanar with each otherand with bottom portion 23., Webs 31 are joined along their upper edgesto the outer edges of panel 15, that is, to the outer edge of theassociated side portion 17, by means of rounded fillets '35; and webs 31are joined to the outer edges of flanges 33, by means of rounded fillets37. Preferably, structural members 13 are formed'by cold forming or hotrolling, in which case fillets 25, 2'7, 35 and 37 have -as small radiias is consisten't with keeping the" 1 of the flooring" members.

' gauge of the sheet metal of the flooring member, the

'29 Within depressed central portion 19. On the other hand, howevcr,'thegreater the divergence of side portions 21 from each other, the greaterwill be their width and hence the greater will be their Weight.Moreover, the greater the divergence of side portions21from each other,the greaterwill be the width and hence the weight of bottom portion 23and also the volume and hence the weight of hardened plastic material-29. Therefore, in an effort to decrease the Weight of the metallicstructural members 13, it is desirable to make side portions 17 as wideas possible ,and side portions21'as-hearlyupright as possible. Ac-

cordingly, it has been found that the preferred angular disposition ofside portions 21is thus about 80 from the horizontal with amanufacturing tolerance of about 2 either way from any selected angle. aThe preferred width of side portions 17, however, is subject tovariation depending on the other dimensions In general, the heavier thewider can bethe side portions 17. On the "other hand,

will be the weight of the structuralmember. For railway rolling stock,fol-example, suitable over-all dimen sions for the metallic structuralmembers for purposes of illustration could be taken as 7% inches inwidth and 1 inches'in height, with the sheet metal of 12 gauge. (0.105inch); For 12-gauge metal, the preferred width of side'portions 17isabout) inches. Notice, there fore; thatthe width of side portions 17yisa little greater than the height of webs 31, andthat the tops of sideportions 21 are spaced from webs 31a distance greater than the height ofwebs 31, but the bottoms of sideportions 21 are-spaced from webs 31 adistance less than the heightofwebs 31, Notice also that the combinedwidth of both side portions 17 is onlyslightlygreater than the 'distancebetween them, so: that considering the slight overlap of hardenedplastic material about fillets 25,

side portions 17;.1 In other words, the area of hardened plasticmaterialexposed tolthe load borne by the flooring is about the same'as the areaof the metal of side pormetal in satisfactory condition during theforming opera;

tion. Where the metal is extruded, however, the external corners of thefillets may be made as close to 90 as is,

desired, bearing in mind that fillets 35 have a nail-guiding functionwhen rounded, as will be explainedin greater de-' portion 23 is of awidth greater than'the distance between side portion 17, and hardenedplastic material 29 within depressed central portion 19 is of a width atits bottom greater than its width at the top. This cross-sectionalconfiguration of depressed central portion 19 is'di-ctate-d by severalfactors. In the first place, it is desirable to make side portions 17 aswide as possible, thereby to reduce the size of depressed centralportion 19 and lighten the structure by reducing the quantity ofhardened plastic material 29 therein. side portions 17 is limited bytheir strength, for when they that Webs 31 extend full height athardened plastic material to a minimum.

On the other hand, however, thewidth of are excessively wide they tendto dish under heavyjloads.

In the second place, it is desirable to incline side portions 21 asshown, in order to lock thehardened plastic material r The exposedsurfaces of side portionslfl and hardened plastic material}? arehorizontal and coplanar, and the umplanar surfaces or the plurality ofstructural .members 13 are in turn coplanar andlhorizontal and arearranged at a uniform level to provide a uniplanar freighte'ngagingface39 of the floor. construction as a whole,

this-face 39 being directed away from the conveying supporting structureandexposed'to the interior of the freight conveyance. i Anotherembodiment era flooring member accordmg to the present invention isshown in cross section in FIGURE 4. As mentioned above, it is desirableto,

keep the weight of the flooring members to a minimum, and one way toxdothis is to reduce the weight of the Accordingly, li'llhe embodimentofrFIGURE 4,.the weight of hardened plastic material 2 9 is reduced byproviding voids therein, these voids being produced by first insertingin depressed central portion 19" a filler in the form of a voidplate 41extending substantially full length of the flooringmember and having aplurality of arches or corrugations therein-such that voids will beproduced beneath the plate, 41 when depressed central portion 19'carrying plate 41' is-filled with hardened plastic'material 29. Plate.41- need only'be of the lightest gauge metal, for example, 29 -gaugesheet steel (0.0141 inch).

The flooring is integrated with the conveying supporting structure bymeans of welds 43 by which atleast some of the webs 31 or flanges 33adjacent fillets 35 are secured toframemembers7, or by other suitablefastening procedures. The flooring is thus secured to the supportingstructure of the conveyance with the opposed flat surfaces of webs 31 ofadjacent structural members 13 parallel to each other and vertical andspaced apart about A of an inch. When the car floor is built up ofsingle structural members, each member may be attached in this orsimilar manner to the car frame. Where the car floor is built up frompanels which in turn are formed of a plurality of preassembledstructural members, not all of the structural members have to be weldedto the car frame.

Between opposed webs 31 is a body of solid elastic deformable material45 of an elasticity such that nails may be driven therein and maydisplace material 45 laterally, but such that when the nails arewithdrawn, the material 45 will recover substantially its originalposition, save for the presence of a rupture along what was formerly theaxis of the nail. It is not necessary that material 45 be self-sealingin the sense that the rupture left by the nail completely heals; on theother hand, preferably, the hole left by the nail should besubstantially reoccupied by material 45 upon withdrawal of the nails.Suitable materials are woven fiber belting impregnated with rubber, asshown for example in the drawing in FIGURE 2, or other fibrous materialimpregnated with rubber or rubbery plastic, or, in general, a solidelastic deformable material, preferably in the form of an impregnant orbinder for a woven or random filament fibrous filler and reinforcingmaterial. Suitable materials, their physical form and arrangement, thespacing between adjacent webs 31, the manner of bonding material 45 tothe webs, and various other aspects of the structure related to elasticdeformable material 45 are discussed in greater detail in copendingapplication Serial No. 74,398, filed December 7, 1960, to whichreference is had for a more complete disclosure of this feature so as toavoid the inclusion of unnecessary disclosure in the presentapplication. Another form of nail-gripping structure which may be usedin the flooring of the present invention is that disclosed in copendingapplication Serial No. 109,750, filed May 12, 1961. Still another formof nail-gripping structure suitable for use in the present invention isshown in the above-mentioned US. Patent No. 2,667,243 in the form ofcomplementarily corrugated adjacent webs, in lieu of fiat webs withsolid elastic deformable material between them. In this last embodiment,the corrugations of the webs grip the nail by deforming it between them.

In any event, it is important to note that either the nailing slot isfilled with a material that substantially completely recovers when anail is withdrawn, as in the case of the straight web embodiments of thepresent invention and of application Serial No. 74,398, or else the nailbut not the web is deformed, as in the case of the corrugated webembodiment of the above-mentioned U.S. Patent No. 2,667,243. In thisWay, the nailing slot can be subjected to repeated driving and pullingof nails, time after time, without itself undergoing any substantialchange.

A mastic material, not shown, may be used to close the slots aboveelastic material 45 to form a smoother floor, but with or without suchmastic filler, the floor can be considered uniplanar for all practicalpurposes.

Bridged welds 47 at widely spaced locations on the freight conveyingsurface of the flooring at the top of the nailing slots integrate thestructural members 9 across the nailing slots between adjacent webs 31,thereby to prevent the webs 31 from pulling away from each other.

The manner of use of the novel flooring according to the presentinvention is also indicated in FIGURE 2, in which a piece of timber 49is shown secured to the metallic floor by means of a nail 51 passingthrough timber 49 and into the nailing slot between webs 31. The timberin turn serves as a stop to prevent certain classes of freight fromshifting about in the car. From the illustrated manner of securingtimber 49 in place, with a nail 51 passing through its midportion, itwill be evident that the provision of a nailing slot wider than the nailis additionally valuable as providing a sufiiciently large target toreduce the chances of missing the nailing slot when the point of thenail emerges from the blind underside of the timber. The chances ofmissing the slot are also reduced by the rounded configuration offillets 35, which help guide poorly aimed nails into the slot.

Flooring members according to the present invent-ion may be made in anyof a variety of ways. Apart from the metal-forming operations describedabove, the plastic material may be inserted in depressed central portion19 either in fluid or in solid state. For example, the upwardly openingcentral portion 19 may be filled with material 29 in a plastic orsemiplastic condition, Whereupon material 29 is then allowed to hardenand the flooring member is complete; or plastic material 29 may beprecast, having such dimensions and shape that it can readily be placedin the central portion 19 and securely anchored in place by means of agrout material com patible with the plastic material 29; afterhardening, the grout and the precast plastic material would be bondedtogether in a monolithic mass.

Plastic material 29 can take any of a variety of forms. It is importantto note, however, that the material 29 will be chosen more from astandpoint of its light weight and load-distributing properties thanfrom a standpoint of its structural strength. This is because material29 does not function primarily to strengthen the flooring members in themanner of a rigid beam. Instead, the principal function of the material29 is to distribute loads more uniformly to the metallic channel memberswhich encase material 29. To perform this function, material 29 must beexposed on its upper surface to the concentrated loads imposed forexample by the wheels of fork lift trucks and the like. The strength ofthe flooring members is essentially the strength of the metal portionsof the members; but by distributing the load more uniformly over themetallic portions of the flooring members, material 29 makes it possibleto reduce the over-all strength, and hence the weight and cost, of themetallic members. Thus, although material 29 would apparently seem toadd to the weight of the flooring members, the upwardly open depressedcentral portion 19 may be designed so that the reduction in the quantityof metal made possible by the use of material 29 is greater than theweight of the material 29 used. Accordingly, a net reduction in theweight of the flooring members can be achieved by the practice of thepresent invention.

Inasmuch as material 29 acts as a load-distributing pad rather than as arigid beam, it also follows that material 29 need not be rigid. Indeed,it is to be expected that in some forms material 29 will to some extentbreak up or become rearranged in use, and this breaking up orrearrangement of the material is largely unobjectionable so long as thematerial is not thereby displaced from central portions 19. It isnecessary, of course, that freight-engaging face 39 be maintainedsubstantially flat, and therefore material 29 should not besubstantially compactible, nor should it be readily displaceable.Various cements and asphalt-bonded compositions are suitable for thepresent invention, it being most desirable, however, that theyincorporate a light-weight filler or aggregate rather than sand orstone. Indeed, the various materials used for road-surfacingcompositions are quite suitable for the present invention, when modifiedby the inclusion of light-weight fillers rather than the customary heavyfillers and, where desired, by the addition of latex or the like. Anumber of plastic flooring compositions are also suitable for use in thepresent invention, such as foamed magnesia cements. As the plasticfiller materials of the present invention are continuously in contact byvolume of expanded shale of the type known as Haydite and in the sizeknown as sand size? This particu lar composition, however, is given onlyby way of ex ample, there being a multitude of other suitablecompositions. a

It is important to note that in addition to minimizing the over-allweight of the flooring members and at the 7 same time increasing theirstrength by distributing the loads imposed thereon, material 29 servesas an antiskid composition that improves the traction of wheeled lifttrucks when loading and unloading freight in the conveyance.Accordingly, it is an important feature of the present'invention thatthe upper surface of material 29 in an unloaded conveyance be exposed.

Finally, it should be noted that oneadvantage of making central portion19 full depth of the flooring member is that bottom portion 23 thereofcan be welded to frame members 7 through holes (not shown) extendingthrough bottom portion 23, thereby to avoid overhead welding during theassembly of :the flooring members in a freightconveyance. Another 'wayof avoiding overhead welding during assembly is to preassemble aplurality of flooring members by means of members spanning a 'group ofthem and attached to the undersides ofthe flooring members. Three orfour of these preassembled groups can then be used to provide a completefloor in a freight conveyance with a minimum of time spent workinginside the conveyance. It is thus relatively easy accurately to predeterButwhether the floormine the width of the nailing slot.

structural members being arranged at a uniform level to provide auniplanar freight-engaging fioor surface, said depressed centralportions of said panels having horizontal bottom portions in contactwith the conveying supportingstructure, saidbottom portions being :widerthan said exposed freight-engaging surfacesof the hardened plasticmaterial, the structural members having webs at either sidethereofxextending from said side portions of the panel downwardtoward'the conveying supporting structure with the depressed centralportion ofthe panel disposed betwecn and spaced from the webs of eachstructural member, downwardly terminating portions of said webs beingcoplanar with the horizontal bottom portions of said depressed centralportion, means including rigid.

connection between the structural members and the conve ying supportingstructure integrating the floor construction and conveying supportingstructure and holding the structural members in' spaced side-by-siderelation in the freight car with webs of adjacent structural members,

contiguous to form a nail-receiving slot therebetween transverse to thelength of the freight car, and nail-gripping meansassociated with theslot.

2i A freight conveyance having conveying supporting structure and afloor construction carried thereby vto which blocking can be nailed forpreventing shifting of freight in' transit, the fioor constructioncomprising a plurality of elongated structural members arranged in Iadjacent side-by-side relation, each structural member comprising apanel havingv a relatively narrow portion on eitherside thereof and arelatively wide depressed upwardly open central portion between saidside portions and extending substantially full length'of the structuralmember arid filled with hardened plastic material, said,

I side portions of the panel and said hardened plastic maing members areinstalled singly or in groups, it is preferred thatthe plastic materialnot be introduced until after installation, thereby to permitthehandling and shipment of the flooring members in as lightweight acondition as possible.

From a consideration of the foregoing disclosure, it will'be obviousthat all of the initially recited objects of the present invention havebeen achieved.

Althoughthe present invention has been described and;

illustrated in connection with preferred embodiments, it

'is to be understood that modifications and variations may.

terial having exposed coplanar freight-engaging upper surfaces whichtogether provide a uniplanar' freight-engaging face of the structuralmember directed away from the conveying supporting structure, eachexposed freightengaging upper surface of said side, portion being narberesorted to without departing from the spirit of the invention, as thoseskilled, in this art will readily 'understand. Such modifications andvariations are considered to be within the purview and scope of thepresent invention as defined by the appended claims.

What is claimed is:

1. Railway rolling stock comprising a freight car elongated in itsdirection of travel and having conveying supporting structure and afloor construction carried thereby to which blocking can be nailed forpreventing shifting of freight in transit, the fioor constructioncomprising a plurality of elongated structural members arranged inadjacentside-by-side relation transverse to the length of the freightcar, each structural member comprising a panel having a relativelynarrow portion on either side thereof and a relatively wide depressedupwardly open central 'portion between said side' portions and extendingsubstantially full length of the structural member and filled withhardened plastic, material, said side portions of the panel and saidhardened plastic material having exposed coplanar freight-engaging uppersurfaces which together provide a uniplanar freight-engagingface of thestructural member directed away from the conveying supporting structure,each exposedfreight-engaging uppersurface of said side portion beingnarrower than the ex- "rower than the exposed freight-engaging surfaceof the hardened plastic materiaL'the freight-engaging faces of theplurality of structural members being arranged at a uniform level toprovide a uniplanar freight-engaging floor surface, said depressedcentral, portions of said panelshaving horizontal bottom portions incontact with the conveying supporting structure, said bottom portionsbeing wider than said exposed freight-engaging surfaces of the hardenedplastic material, the structural members having webs at either sidethereof extending from said side portions of the panel downward towardthe conveying supporting structure with the depressed central portion ofthe panel disposed between and spaced fromvthe webs of each structuralmemben'downwardly terminating portions of said webs being coplanar withthehorizontal bottom portions of said depressed central portion, meansincluding rigid connection between the structural members and therconveying supporting structure integrating the floor construction andconveying supporting structure and holding the structural members inspaced side-by-side relation in the freight conveyancewith webs ofadjacent structural members contiguous to form a nail-receiving slottherebetween, and nail-gripping means associated \m'th the'slot. L' i g3. 'A freight conveyance as claimed in claim 2, said depressed centralportion of the panel having flat bottom and side portions, the latterside portions being oppositely inclined from the vertical at angles ofabout 10.

4. A freight conveyance as claimed in claim 2, said webs terminatingdownward in flanges disposed in a common plane parallel to said'freight-engaging face.

5. A freightconveyance as claimed inclaim 4, said flanges being coplanarwith the bottom of said depressed central portion of theassociatedpanel.

f 6. Freight conveyance floor construction comprising a plurality ofelongated structural members, means rigidly securing the structuralmembers together in adjacent side-by-side relation, each structuralmember comprising a panel having a relatively narrow horizontal portionon either side thereof and a relatively wide depressed upwardly opencentral portion between said side portions extending substantially fulllength of the structural member and having upper terminal portionsdefining a horizontal spacing coplanar with said side portions, saiddepressed upwardly open central portion having a horizontal bottomportion being wider than said horizontal spacing coplanar with said sideportions, said side portions of the panel having exposed coplanarfreight-engaging upper surfaces which together provide a uniplanarfreight-engaging face of the structural member, each exposedfreight-engaging upper surface being narrower than said horizontalspacing coplanar with said side portions, the structural member havingwebs at either side thereof ex tending from said side portions of thepanel away from said freight-engaging face in the same direction and forabout the same distance as said depressed central portion of the panel,downwardly terminating portions of said webs being coplanar with thehorizontal bottom portions of said depressed upwardly open centralportion, with the depressed central portion of the panel disposedbetween and spaced from the webs of the structural member, the webs ofadjacent structural members being contiguous and having a nail-receivingslot thcrebetween, and nail-gripping means associated with the slot.

7. Freight conveyance floor construction as claimed in claim 6, saiddepressed central portion of the panel being filled with hardenedplastic material having an exposed surface coplanar with the associatedfreight-engaging face of the structural member.

8. Freight conveyance floor construction comprising an elongatedstructural member in the form of a panel having a relatively narrowhorizontal portion on either side thereof and a relatively widedepressed upwardly open central portion between said side portionsextending substantially full length of the structural member and havingupper terminal portions defining a horizontal spacing coplanar with saidside portions, said depressed upwardly open central portion having ahorizontal bottom portion being wider than said horizontal spacingcoplanar with said side portions, said side portions of the panel havingexposed coplanar freight-engaging upper surfaces which together providea uniplanar freightengaging face of the structural member, each exposedfreight-engaging upper surface being narrower than said horizontalspacing coplanar with said side portions, the structural member havingWebs at either side thereof extending from said side portions of thepanel away from said freight-engaging face in the same direction and forabout the same distance as said depressed central portion of the panel,downwardly terminating portions of said webs being coplanar with thehorizontal bottom portion of said depressed upwardly open centralportion, with the depressed central portion of the panel disposedbetween and spaced from the webs of the structural member.

9. Freight conveyance floor construction as claimed in claim 8, saiddepressed central portion of the panel being filled with hardenedplastic material having an exposed surface coplanar with the associatedfreight-engaging face of the structural member.

10. Freight conveyance fioor construction as claimed in claim 8, saiddepressed central portion of the panel having flat bottom and sideportions, the latter side portions being oppositely inclined from thevertical at angles of about 10.

11. Freight conveyance floor construction as claimed in claim 8, saidwebs terminating away from said freightengaging face in flanges disposedin a common plane parallel to said freight-engaging face.

12. Freight conveyance floor construction as claimed in claim 11, saidflanges being coplanar with the bottom of said depressed central portionof the associated panel.

References Cited by the Examiner UNITED STATES PATENTS 2,017,832 10/35Hovey 18934 2,106,390 1/38 Crane --422 2,388,968 11/45 Hedgren 105-4222,692,032 10/54 Peterson 105-422 2,739,543 3/56 Candlin 105-4222,794,403 6/57 Stein 105--422 2,907,417 10/59 Doerr 105-422 2,942,7016/60 Pope 105422 3,004,640 10/ 61 Macomber 189-34 3,132,604 5/64 Collinset al. 105422 3,132,605 5/64 Collins 105-422 LEO QUACKENBUSH, PrimaryExaminer.

8. FREIGHT CONVEYANCE FLOOR CONSTRUCTION COMPRISING AN ELONGATEDSTRUCTURAL MEMBER IN THE FORM OF A PANEL HAVING A RELATIVELY NARROWHORIZONTAL PORTION ON EITHER SIDE THEREOF AND A RELATIVELY WIDEDEPRESSED UPWARDLY OPEN CENTRAL PORTION BETWEEN SAID SIDE PORTIONSEXTENDING SUBSTANTIALLY FULL LENGTH OF THE STRUCTURAL MEMBER AND HAVINGUPPER TERMINAL PORTIONS DEFINING A HORIZONTAL SPACING COPLANAR WITH SAIDSIDE PORTIONS, SAID DEPRESSED UPWARDLY OPEN CENTRAL PORTION HAVING AHORIZONTAL BOTTOM PORTION BEING WIDER THAN SAID HORIZONTAL SPACINGCOPLANAR WITH SAID SIDE PORTIONS, SAID SIDE PORTIONS OF THE PANEL HAVINGEXPOSED COPLANAR FREIGHT-ENGAGING UPPER SURFACES WHICH TOGETHER PROVIDEA UNIPLANAR FREIGHTENGAGING FACE OF THE STRUCTURAL MEMBER, EACH EXPOSEDFREIGHT-ENGAGING UPPER SURFACE BEING NARROWER THAN SAID HORIZONTALSPACING COPLANAR WITH SAID SIDE PORTIONS, THE STRUCTURAL MEMBER HAVINGWEBS AT EITHER SIDE THEREOF EXTENDING FROM SAID SIDE PORTIONS OF THEPANEL AWAY FROM SAID FREIGHT-ENGAGING FACE IN THE SAME DIRECTION AND FORABOUT THE SAME DISTANCE AS SAID DEPRESSED CENTRAL PORTION OF THE PANEL,DOWNWARDLY TERMINATING PORTIONS OF SAID WEBS BEING COPLANAR WITH THEHORIZONTAL BOTTOM PORTION OF SAID DEPRESSED UPWARDLY OPEN CENTRALPORTION, WITH THE DEPRESSED CENTRAL PORTION OF THE PANEL DISPOSEDBETWEEN AND SPACED FROM THE WEBS OF THE STRUCTURAL MEMBER.